Seamless attachment of pre-formed footwear components

ABSTRACT

An item of footwear comprises an upper having a first overlap area and the bottom having a second overlap area. The upper is attached to the bottom by stitching high frequency adhesive tape to the overlap area of the upper and separately to the overlap area of the bottom. The upper and the bottom are brought together so that the two overlap areas are in solid contact with one another when the footwear is subjected to the high frequency signal which turns the solid adhesive tapes into a molten liquid. When the liquid cools, the upper and bottom are welded to one another. The seal between the components is waterproof.

Applicant Claims The Benefit Of U.S. Provisional Patent Application Ser.No. 61/701,320 Filed On Sep. 14, 2012

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to footwear having two or more componentsattached together by high frequency adhesives and to a method ofattaching the components to one another without stitching any componentstogether.

2. Description of the Prior Art

Attaching two or more parts together using adhesives or high frequencyadhesives is known.

In U.S. Pat. No. 7,556,861 issued on Jul. 7, 2009 for High FrequencyWeldable Articles and a Method of Constructing the same, there isdescribed high frequency-weldable articles and method for connecting thearticles.

When two or more components of footwear are presently attached to oneanother, the overlapping areas of the two or more components are coatedwith adhesive and the components are stitched together along theoverlapping areas. For example, an upper of a boot can be attached to amiddle of a boot in this manner. A disadvantage of this method is thatthe boot is not waterproof at the joint where the two components arejoined to one another because of the openings created by stitching thetwo components together. The two components will therefore allow waterto leak into the boot along the joint. It is also known to join twofootwear components to one another by using adhesives without stitching.However, when stitching is not used, for example, to join an upper to amid sole, the joint is not strong enough to withstand the stress thatfootwear is subjected to and will often fail prematurely.

SUMMARY OF THE INVENTION

It is an object to the present invention to bring together twocomponents of an item of footwear using high frequency welding and highfrequency adhesives in which the adhesives are affixed to theoverlapping area of each of the components to be joined by stitching thehigh frequency adhesives to each component separately. It is a furtherobject of the present invention to hold the two components to beattached to one another together with the overlap areas and the highfrequency adhesives aligned with one another and subjecting the highfrequency adhesives to a high frequency signal to weld the twocomponents together. The finished product has no stitching openingsextending through the two components and the stitching openings that hadbeen contained in each of the two components prior to welding are filledwith solidified adhesive. The two components are welded together with astrength that is durable and will not result in premature failure whensubjected to stress that footwear components are subjected to. The wellcan be as strong or stronger than the bond between components that areglued and stitched together. The resulting seam between the twocomponents is waterproof.

An item of footwear comprises a first component and a second component,the first component having a first overlap area and the second componenthaving a second overlap area. The components are footwear components andare sized and shaped to be attached to one another in the overlap areas,the first overlap area having a first high frequency adhesive stitchedthereto and the second overlap area having a second high frequencyadhesive stitched thereto. The first high frequency adhesive iscompatible to bond with the first component and the second highfrequency adhesive is compatible to bond with the second component. Thefirst and second high frequency adhesives are compatible to bond withone another when the two components are held in a position to attach thetwo components to one another in the first and second overlap areas withthe first and second high frequency adhesives in contact with oneanother, the high frequency adhesives being subjected to a highfrequency signal to cause the first and second components to weld to oneanother along the first and second overlap areas.

A method of attaching a first component of an item of footwear to asecond component of an item of footwear uses high frequency adhesives,the first component having a first overlap area and the second componenthaving a second overlap area. The method comprises choosing compatiblehigh frequency adhesives, stitching a first high frequency adhesive tothe first overlap area and stitching a second high frequency adhesive tothe second overlap area, the first overlap area and the second overlaparea being sized relative to one another, holding the first overlap areain contact with the second overlap area with the first and second highfrequency adhesives in between, subjecting the high frequency adhesivesto a high frequency signal to cause the high frequency adhesives to bondtogether, thereby fusing the first and second components to one anotherwith no stitch openings extending through both the first and secondoverlap areas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a boot when viewed from one side;

FIG. 2 is an exploded perspective view of a boot where a bottom isseparated from an upper; and

FIG. 3 is a partial perspective view of an overlap area of the upper.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

In FIG. 1, a boot 2 has an upper 4 affixed to a bottom 6. The bottom 6has a sole 8 and a midsole 10. The upper 4 is attached to the midsole 10of the bottom 6 along a joint 12.

In FIGS. 2 and 3, the bottom 6 has a first overlap area 14 and the upper4 and a second overlap area 16. The bottom 6 and upper 4 are locatedseparate and apart from one another in FIG. 2. The first overlap area 14has a first adhesive 18 affixed thereto by stitching 20. The secondoverlap area 16 has a second adhesive 22 affixed thereto by stitching24. When the first adhesive 18 and the second adhesive 22 are in placeas shown, the upper 4 and the bottom 6 are brought together so that thetwo overlap areas 14, 16 are in contact with one another with the twoadhesives 18, 22 located in between. The respective stitching preferablyextends along the overlap areas substantially one end to the other endas do the respective adhesives. In the drawings, the stitching 20, 24 isonly partially shown. The respective adhesives are not shown in thedrawings in the overlap areas where the stitching is located so as notto observe the stitching.

With the upper 4 and the bottom 6 held in the contact position, the highfrequency adhesives 18, 22 are subjected to a high frequency signal,which causes the two overlapped areas 14, 16 to be welded to oneanother.

Since the stitching 20 extends only through the first overlap area 14 ofthe bottom 6 and the stitching 24 extends only through the secondoverlap area 16 of the upper 22, there is no stitching that extendsthrough both the bottom and the upper and the stitch openings in thebottom are generally not aligned with the stitch openings in the upper.However, even if some of the stitch openings in the bottom are alignedwith the stitch openings in the upper, after the high frequency weldingprocess, the high frequency adhesives 18, 22 solidify and fill thethreaded openings in the bottom 6 and in the upper 4.

The high frequency welding produces a strong bond between the bottom andthe upper that is at least as strong as stitching the upper and bottomtogether with adhesives located therebetween. The boot, shoe or otherfootwear is completely waterproof along the joint between the upper andthe bottom when constructed in accordance with the present invention.

The upper can be made of nylon, fabrics, or coated fabrics, for example,polyurethane and leathers and the bottom can be made of differentmaterials, for example, ethylene vinylacetate, thermoplastic rubber,polyurethane, polyvinylchloride, rubber, thermoplastic urethane or otherplastics.

Projection molding, compression molding, or vulcanization can be used tocreate a bottom or sole.

The adhesive is preferably a tape, yarn or other preformed solidadhesive that is compatible with the material of the upper and thematerial of the midsole of the bottom or the bottom where the upper isattached directly to the sole. For example, modified polyethyleneterephthalate can be used as solder in high frequency welding to weldcompatible materials to one another.

No stitches extend through both the overlap area of the upper and theoverlap area of the bottom. One adhesive is preferably sewn onto theinner surface of the upper and another adhesive is preferably sewn ontothe outer surface of the bottom. When the high frequency tapes or otheradhesives are subjected to a high frequency signal while the two overlapareas are held in contact with one another, the tapes or other adhesivesmelt and, when the joint between the upper and the bottom cools, theadhesives have filled any stitch openings in either the upper or thebottom. There are no single stitch openings at any time that extendthrough both the upper and the bottom. The high frequency tape or otheradhesive acts as a solder.

While an upper is described as being affixed to the bottom, the productand method of the present invention can be used to attach any two ormore components of an item of footwear together.

1. An item of footwear comprising a first component and a secondcomponent, the first component having a first overlap area and thesecond component having a second overlap area, the components beingfootwear components and being sized and shaped to be attached to oneanother in the overlap areas, the first overlap area having a first highfrequency adhesive stitched thereto and the second overlap area having asecond high frequency adhesive stitched thereto, the first highfrequency adhesive being compatible to bond with the first component,the second high frequency adhesive being compatible to bond with thesecond component, the first and second high frequency adhesives beingcompatible to bond with one another when the two components are held ina position to attach the two components to one another in the first andsecond overlap areas with the first and second high frequency adhesivesin contact with one another, the high frequency adhesives beingsubjected to a high frequency signal to cause the first and secondcomponents to weld to one another along the first and second overlapareas.
 2. The item of footwear as claimed in claim 1 wherein there areno single stitching openings extending through both the first and secondoverlap areas when the first and second components are joined together.3. The item of footwear as claimed in claim 1 wherein the components arepre-formed.
 4. The item m of footwear as claimed in claim 1 wherein thefirst component is an upper and the second component is a bottom.
 5. Theitem of footwear as claimed in claim 1 wherein the first component is anupper shaft and the second component is a bottom, the footwear being aboot.
 6. The item of footwear as claimed in claim 1 wherein the highfrequency adhesives are identical to one another.
 7. The item offootwear as claimed in claim 1 wherein stitch openings in each of thetwo components are filled with solidified adhesive after the twocomponents are welded to one another.
 8. A method of attaching a firstcomponent of an item of footwear to a second component of an item offootwear using high frequency adhesives, the first component having afirst overlap area and the second component having a second overlaparea, the method comprising choosing compatible high frequencyadhesives, stitching a first high frequency adhesive to the firstoverlap area and stitching a second high frequency adhesive to thesecond overlap area, the first overlap area and the second overlap areabeing sized relative to one another, holding the first overlap area incontact with the second overlap area with the first and second highfrequency adhesives in between, subjecting the high frequency adhesivesto a high frequency signal to cause the high frequency adhesives to bondtogether, thereby fusing the first and second components to one anotherwith no stitch openings extending through both the first and secondoverlap areas.
 9. The method as claimed in claim 8 including the step ofchoosing the first and second adhesives to be identical to one another.